The invention relates to a sheet material de-stacking machine for removing a partial stack from a stack of sheet material, comprising a table top horizontally slidably mounted on a frame and a drivable separating roller which is arranged on a front edge of the table top to be inserted into the stack of sheets.
De-stacking machines of this kind are known and used in such a manner that the table top, with the rotating separating roller, is introduced into the stack of sheets at a predetermined height in order to separate and lift clear the upper part from the remainder of the stack and then move it away on the table top. If the stack of sheet material is tilted slightly to the front edge of the table top so that the horizontally moving separating roller first comes into contact with a corner of the stack of sheet material and if, after this coming into contact, the table top is moved slightly upwardly into the stack, the separating roller can also effect the initial separation of the partial stack to be removed from the remaining stack at the said corner and subsequently over the entire width of the stack, i.e., it is then unnecessary for the partial stack to be previously raised by hand along one edge and, for example, for an angle section to be introduced.
These known de-stacking machines generally operate in a quite satisfactory manner. However, with very smooth and/or thin sheet material it happens, particularly if the partial stack to be removed is relatively heavy, that the lowest sheet or lowest few sheets of the partial stack are displaced and/or crumpled at the end of the operation of introducing the separating roller and table top into the stack.
It is therefore an object of the invention to provide a de-stacking machine of the type set forth with means capable of preventing this phenomenon.